Migrate EPP/Email from Soy to JAXB/FreeMarker (#3038)

- Replace deprecated Soy templates for EPP XML with JAXB models and a refined Fluent DSL.
- Migrate Spec11 and administrative emails to FreeMarker with HTML auto-escaping.
- Remove Soy compiler, Gradle tasks, and library dependencies.
- Address PR feedback regarding shadowing, version locking, and security warnings.
- Enhance tests with comprehensive XML equality assertions using Java 15 text blocks.
- Improve Javadocs and maintain strict temporal consistency using java.time.

FreeMarker replaces Soy for email templating, providing native HTML auto-escaping and allowing the removal of the complex 'soyToJava' compilation step from the build process. This significantly simplifies the build system and reduces maintenance overhead. For EPP XML, migrating to JAXB allows tool-generated commands to use the same model classes as the server-side EPP flows. This ensures that tool-generated XML is always schema-compliant and eliminates the risk of divergence between tool templates and actual server-side implementation. This unified approach provides compile-time type safety and improves developer ergonomics via a refined fluent DSL.

The base ImmutableObject class now provides a public clone() override that correctly resets the cached hashCode to null. This centralizes the custom cloning logic previously handled by a static helper and ensures that all subclasses—including the newly added JAXB models—satisfy CodeQL security requirements without needing redundant per-class overrides. The legacy static clone(T) helper has been updated to delegate to this instance method to maintain compatibility and architectural consistency.

config/presubmits.py

@@ -90,15 +90,15 @@ PRESUBMITS = {
     # License check
     PresubmitCheck(
         r".*Copyright 20\d{2} The Nomulus Authors\. All Rights Reserved\.",
-        ("java", "js", "soy", "sql", "py", "sh", "gradle", "ts"), {
+        ("java", "js", "sql", "py", "sh", "gradle", "ts", "ftl"), {
             ".git", "/build/", "node_modules/", "LoggerConfig.java", "registrar_bin.",
             "registrar_dbg.", "google-java-format-diff.py",
-            "nomulus.golden.sql", "soyutils_usegoog.js", "javascript/checks.js"
+            "nomulus.golden.sql", "javascript/checks.js"
         }, REQUIRED):
         "File did not include the license header.",
 
     # Files must end in a newline
-    PresubmitCheck(r".*\n$", ("java", "js", "soy", "sql", "py", "sh", "gradle", "ts", "xml"),
+    PresubmitCheck(r".*\n$", ("java", "js", "sql", "py", "sh", "gradle", "ts", "xml", "ftl"),
                    {"node_modules/", ".idea"}, REQUIRED):
         "Source files must end in a newline.",
 
@@ -127,33 +127,6 @@ PRESUBMITS = {
         "System.(out|err).println is only allowed in tools/ packages. Please "
         "use a logger instead.",
 
-    # Various Soy linting checks
-    PresubmitCheck(
-        r".* (/\*)?\* {?@param ",
-        "soy",
-        {},
-    ):
-        "In SOY please use the ({@param name: string} /** User name. */) style"
-        " parameter passing instead of the ( * @param name User name.) style "
-        "parameter passing.",
-    PresubmitCheck(
-        r'.*\{[^}]+\w+:\s+"',
-        "soy",
-        {},
-    ):
-        "Please don't use double-quoted string literals in Soy parameters",
-    PresubmitCheck(
-        r'.*autoescape\s*=\s*"[^s]',
-        "soy",
-        {},
-    ):
-        "All soy templates must use strict autoescaping",
-    PresubmitCheck(
-        r".*noAutoescape",
-        "soy",
-        {},
-    ):
-        "All soy templates must use strict autoescaping",
     PresubmitCheck(
         r".*\nimport\s+(?:static\s+)?.*\.shaded\..*",
         "java",